cd

, chdir

, pushd

, popd

, dirs

- change working directory

用法概要

/usr/bin/cd [directory]

sh

cd [argument]

chdir [argument]

csh

cd [dir]

chdir [dir]

pushd [+n | dir]

popd [+n]

dirs [-l]

ksh88, ksh

cd [-L] [-P] [arg]

cdoldnew

描述

/usr/bin/cd

The /usr/bin/cd utility changes the current directory in the context of the
cd utility only. This is in contrast to the version built into
the shell. /usr/bin/cd has no effect on the invoking process but can
be used to determine whether or not a given directory can be set
as the current directory.

sh

The Bourne shell built-in cd changes the current directory to argument. The
shell parameter HOME is the default argument. The shell parameter CDPATH defines
the search path for the directory containing argument. Alternative directory names are separated
by a colon (:). The default path is <null> (specifying the current
directory). The current directory is specified by a null path name, which
can appear immediately after the equal sign or between the colon delimiters anywhere
else in the path list. If argument begins with `/', `.', or
`. .', the search path is not used. Otherwise, each directory in the
path is searched for argument. cd must have execute (search) permission in argument.
Because a new process is created to execute each command, cd would
be ineffective if it were written as a normal command; therefore, it is
recognized by and is internal to the shell. (See pwd(1), sh(1), and
chdir(2)).

chdir is just another way to call cd.

csh

If dir is not specified, the C shell built-in cd uses the
value of shell parameter HOME as the new working directory. If dir
specifies a complete path starting with `/', `.', or `. .', dir becomes the
new working directory. If neither case applies, cd tries to find the
designated directory relative to one of the paths specified by the CDPATH
shell variable. CDPATH has the same syntax as, and similar semantics to, the
PATH shell variable. cd must have execute (search) permission in dir. Because
a new process is created to execute each command, cd would be
ineffective if it were written as a normal command; therefore, it is recognized
by and is internal to the C-shell. (See pwd(1), sh(1), and chdir(2)).

chdir changes the shell's working directory to directory dir. If no argument
is given, change to the home directory of the user. If dir
is a relative pathname not found in the current directory, check for
it in those directories listed in the cdpath variable. If dir is the
name of a shell variable whose value starts with a /, change
to the directory named by that value.

pushd pushes a directory onto the directory stack. With no arguments, exchange
the top two elements.

+n

Rotate the n'th entry to the top of the stack and cd to it.

dir

Push the current working directory onto the stack and change to dir.

popd pops the directory stack and cd to the new top directory.
The elements of the directory stack are numbered from 0 starting at
the top.

+n

Discard the n'th entry in the stack.

dirs prints the directory stack, most recent to the left; the first
directory shown is the current directory. With the -l argument, produce an
unabbreviated printout; use of the ~ notation is suppressed.

ksh88, ksh

The Korn shell built-in cd command can be in either of two
forms. In the first form it changes the current directory to arg.
If arg is - the directory is changed to the previous directory.
The shell variable HOME is the default arg. The environment variable PWD is
set to the current directory. If the PWD is changed, the OLDPWD
environment variable shall also be changed to the value of the old
working directory, that is, the current working directory immediately prior to the call
to change directory (cd). The shell variable CDPATH defines the search path
for the directory containing arg. Alternative directory names are separated by a colon
(:). The default path is null (specifying the current directory). The current
directory is specified by a null path name, which can appear immediately
after the equal sign or between the colon delimiters anywhere else in
the path list. If arg begins with a `/', `.', or `. .',
then the search path is not used. Otherwise, each directory in the
path is searched for arg. If unsuccessful, cd attempts to change directories to
the pathname formed by the concatenation of the value of PWD, a
slash character, and arg.

If both -L and -P options are specified, the last option to
be invoked is used and the other is ignored. If neither -L
nor -P is specified, the operand is handled dot-dot logically.

The second form of cd substitutes the string new for the string
old in the current directory name, PWD and tries to change to
this new directory.

The cd command cannot be executed by rksh. Because a new process
is created to execute each command, cd would be ineffective if it
were written as a normal command; therefore, it is recognized by and
is internal to the Korn shell. (See pwd(1), sh(1), and chdir(2)).

操作数

The following operands are supported:

directory

An absolute or relative pathname of the directory that becomes the new working directory. The interpretation of a relative pathname by cd depends on the CDPATH environment variable.

OUTPUT

If a non-empty directory name from CDPATH is used, an absolute pathname
of the new working directory is written to the standard output as
follows:

"%s\n", <new directory>

Otherwise, there is no output.

环境变量

See environ(5) for descriptions of the following environment variables that affect the
execution of cd: LANG, LC_ALL, LC_CTYPE, LC_MESSAGES, and NLSPATH.

CDPATH

A colon-separated list of pathnames that refer to directories. If the directory operand does not begin with a slash (/) character, and the first component is not dot or dot-dot, cd searches for directory relative to each directory named in the CDPATH variable, in the order listed. The new working directory sets to the first matching directory found. An empty string in place of a directory pathname represents the current directory. If CDPATH is not set, it is treated as if it were an empty string.

HOME

The name of the home directory, used when no directory operand is specified.

OLDPWD

A pathname of the previous working directory, used by cd-.

PWD

A pathname of the current working directory, set by cd after it has changed to that directory.